Vertically storing dock leveler

ABSTRACT

A seal for a vertically storing dock leveler employs a foam pad connected to the underside of the deck. As the leveler is lowered, the pad contacts the shelf on to which the leveler is mounted and deflects inward and compresses to seal the space between the underside of the leveler and the shelf. The pad is a tapered foam with a fabric covering.

BACKGROUND OF THE INVENTION

This application is a continuation of application Ser. No. 07/669,128,now abandoned, which is a continuation-in-part of application Ser. No.07/331,983 filed on Apr. 3, 1990 now U.S. Pat. No. 5,001,799.

This invention relates to dock levelers and in particular, to levelerswhich store vertically. Such devices are used at loading docks to bridgethe distance between a truck to be loaded, or unloaded, and the interiorof a warehouse, storage facility, or the like. In general, these devicesaccommodate for both the distance between the end of the truck and thedock facility, and the vertical truck "float" as it is loaded andunloaded. That is, the truck will move vertically depending on its stateof loading.

For this purpose, dock levelers utilize a lip which extends onto thetruck deck and is movable in response to truck float. Generally, suchlevelers fall into two categories, those which store horizontally withthe lip in a downward or pendent position and those which storevertically with the lip generally upward. In both cases, when not in usea roll-down door or the like is used to seal the opening. When the truckbacks into the dock for purposes of loading or unloading, the door isopened and the space is generally sealed by means of fixed or adjustabledock seals comprising foam, fabric, inflatable cells or the like whichare mounted on the sides of the dock and at the header or top. Suchseals are well known and are in common use. In the case of horizontallystored dock levelers, since they are generally mounted into a pit orrecess there is no open area underneath the leveler which requires aweather seal.

In contrast, in the case of vertically storing levelers there is apropensity for heat loss or entry into a building since the leveler isgenerally on a shelf rather than in a pit. In the past, to seal thisarea it has been conventional to use a pad mounted to the bottom of theface of the building under the dock leveler. However, because the dockleveler lip must be lowered to service a truck which is fully loaded,such a bottom pad is usually complex and has a pocket which in turnbecomes a trap for debris. Additionally, such a structure is vulnerableto impact damage by trucks.

Another problem with vertically storing levelers is that the lip isnarrower than the truck width. The dock opening thus has exposed sideswhich permits heat transfer. Conventional wedges and side pads do noteffectively seal this area. A sealing mechanism is thus required whichat the same time allows the leveler to move vertically into the storedposition when not in use.

SUMMARY OF THE INVENTION

Given this deficiency in the prior art, it is an object of thisinvention to provide an improved vertically storing dock leveler whichcarries its own seal.

Yet another object of this invention is a seal for a vertically storingdock leveler which deflects inward and compresses to seal the area fromthe underside of a lowered dock leveler to the shelf.

Yet another advantage of this invention is to provide for an improvedseal usable with a vertically storing dock leveler which has an extendedrange of deflection to accommodate for various truck heights as thetruck is loaded and unloaded yet still provide a weather seal for theunderside of the leveler.

These and other objects of this invention are accomplished by means of avertically storing dock leveler which employs a deck seal attached tothe underside of the leveler deck. The seal is constructed of aresilient foam. The seal maybe a wedged shaped pad which deflectsthrough bending rather than pure compression. By deflecting,compensation for varying heights of the deck assembly is achieved. Bythis invention, a unitary seal across the front of the leveler isprovided.

The seal may be fixed or hang for pivoting action as the deck and israised or lowered. Also, the side seals provide a wedge between the dockand lip to seal the space when the leveler is lowered.

This invention will be described in greater detail by referring to theattached drawing and the description of the preferred embodiment thatfollows.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a front elevation of the vertically stored dock leveler inaccordance with this a first preferred embodiment of this invention;

FIG. 2 is an end sectional view of the dock leveler of FIG. 1illustrating the leveler in the vertical stored position, and in thehorizontal position with the lip in a lower pendant position such thatthe board is at its lowest most point of travel,

FIG. 3 is an enlarged partial end view illustrating the details ofattachment,

FIG. 4 is an enlarged partial front view illustrating deflection overthe hydraulic cylinder,

FIG. 5 is an enlarged view showing further details of attachment of theseal,

FIGS. 6A, 6B and 6C illustrate side views of a second preferredembodiment of a bottom seal with the leveler stored vertically, extendedin an operative position and extended in a below dock level position,and FIGS. 7A, 7B, 7C and 7D illustrate a side view, front view plan viewand partial sectional view of a third embodiment of this invention usingside wiper extensions to provide a seal.

DESCRIPTION OF PREFERRED EMBODIMENTS

As illustrated in the drawings, this invention relates to a verticallystored dock leveler 10. The leveler is mounted onto a loading dock 12which itself has a pit which is located at an elevation below that ofthe dock surface 12. While not illustrated, the leveler is mounted in adoorway of a building, the doorway generally being closed by an overheaddoor, also not shown. Surrounding that doorway, conventionally foamseals are used to provide a technique by which the outer walls of atruck contact the resilient material and a deformation to seal theopening as the truck is loaded or unloaded.

The dockboard or leveler 10 comprises, generally, a support structure ora frame 16 which extends outwardly from a channel 18 which is embeddedto the rear wall of the pit by means of anchors 20 or the like. Mountingmembers or lugs 22 form a part of the frame to which the dockboard ishinged via lugs 24 and a hinge pin 26. As illustrated in FIG. 1, foursuch points of attachment are illustrated.

The leveler further comprises a deck surface 28 supported by a series ofparallel beams 30. Those beams may take any conventional form such asI-channel, C-channel, or the like. In the case of fixed hinges, asillustrated herein, it is preferable that the beams 30 be a split boxbeam to reduce torsional loading on the dock leveler, yet maintain andprovide the necessary strength.

The leveler also includes a lip 32 which is pivotally connected to thedeck by means of a hinge 34. The lip 32 is movable independently of theposition of the deck by means of hydraulic cylinder 36. The hydrauliccylinder 36 has one end attached to the lower portion of the deck bymeans of pivot pin 38 with its piston rod hinged to the lip 32 by meansof pin 40.

Movement of the deck itself is achieved by means of hydraulic cylinder42. The cylinder has its lower end pivotally connected to a series oflugs by means of pivot pin 44. The upper end thereof is pivotallyconnected to the deck by means of lugs 46 and pivot pin 48. It will beappreciated by those knowledgeable in this technology that while ahydraulic cylinder is used for actuation of both the lip 32 and the deck28, other types of actuation may be employed.

The leveler also includes a toggle lock assembly having a pair of links50 and 52. That lock assembly is actuated by means of a pull chain andarm 54. Such an assembly may be that which is disclosed in U.S. Pat. No.4,776,052.

In accordance with this invention a bottom pad 60 is employed whichcomprises a resilient foam having a fabric cover. The bottom pad issecured to the underside of the deck allowing only an opening foractuation by the hydraulic cylinder 36 for lip actuation.

FIG. 2 illustrates the dock leveler in two positions. In the verticalstored position the lip 32 is disposed generally upward. As can be seen,the foam is a wedge shape which protrudes slightly backward from theforward most portion of the dock leveler.

As the dock leveler is lowered, the distal end of the pad 60 contactsthe pit surface 14. Continued downward motion of the leveler, asillustrated in FIG. 2, causes rearward deflection of the foam pad. Giventhe size of the pad, sealing occurs at first contact with the pit 14 andcontinues as the leveler moves further downward to accommodate a truckas it is being loaded. It will be appreciated that as the truck isunloaded and the leveler raises while the deflection of the pad willreduce, sealing will still occur.

Thus, in accordance with this invention the mode of sealing is primarilyone of deflection rather than compression. The use of a conventionalfoam pad system would require a significant amount of compression at thelowest position and that force of compression would impede the abilityof the pad to recover its shape. By allowing the pad to deflect, agreater range of dock leveler operation is achieved, with the foam paddeflecting under less force.

An important advantage of this system is that when the leveler is in itsvertical raised position as illustrated in FIG. 2, the pit area is cleanand unobstructed allowing debris to be removed. Additionally, as furtherillustrated in FIG. 2 since the pad is located on the underside of theleveler, no part of the truck can come in contact with it. Thus, damagefrom truck movement, a forklift truck operation, or the like isaffirmatively prevented.

FIG. 2 also illustrates side rails 62. Those rails are necessary giventhe shelf mounting of the vertically stored leveler to prevent forkliftsand the like from inadvertently falling off the side of the unit.

Referring now to FIGS. 3, 4, and 5, the details of attaching the pad 60to the underside of the leveler are depicted. In accordance with thisinvention, the fabric cover of the seal is sewn into a tube or sleeve oneach side of the seal. These are illustrated as elements 62, 64. A stripof metal 66 (see FIG. 5) is inserted into each sleeve and the seal isattached to the deck by means of screws 68. Those screws are generallyinserted through the strips into the deck beams 30. By this technique,the strip provides clearance over which the hydraulic cylinder 36 or anyother component may protrude beyond the beams. Consequently, using thistechnique a continuous seal may be formed thus, affectively not havingany gaps between the underside of the deck and the housing.

Referring now to FIGS. 6A, 6B and 6C a second preferred embodiment ofthis invention is illustrated. In this embodiment the bottom pad 70differs from that in the first embodiment in that it is attached bymember 72 to the underside of the leveler 10 for pivoting movement.Member 72 may be a hinge or the seal cover itself affixed to the deckwith the fabric providing the flex point. As illustrated in FIG. 6A andFIG. 6B, the bottom pad hangs pendant and contacts the pit surface 14when the deck is lowered. When the deck is in the raised stored positionshown in FIG. 6A the pad 70 sits essentially flush to the undersidethereof. By this technique unwanted protrusions are eliminated. In thelowered position illustrated in FIG. 6B, the bottom pad 70 seals thespace below the leveler as in the first embodiment.

The pad 70 is configured for buckling compression as opposed to bulgingwhen used in a below dock mode as illustrated in FIG. 6C. Buckling is apreferred mode of deformation since the pad bends at a predictable pointthus eliminating billowing of the covering fabric. The pad 70 has agenerally flat outwardly projecting surface 74 and a pair of inwardlyprojecting surfaces 76, 78, that form an obtuse angle. As illustrated,the maximum cross-sectional thickness of the pad 70 is near the centerwith the thickness tapering to each end. With this configuration the pad70 has sufficient strength to seal yet slightly yield as vehicles passover the deck in the cross traffic position of FIG. 6B. However, asillustrated in FIG. 6C when the leveler 10 is lowered for operationbelow dock level the pad 70 will buckle, deflecting with lesscompression of the foam. This buckling mode of deformation thusminimizes billowing of the cover since it is in tension.

The bottom pad 70 typically has a length substantially equal to thewidth of the deck. It may, however, be extended laterally beyond thedeck to provide a seal extending the width of the dock. In accordancewith this invention an additional pad system is used to seal the sides.Conventionally, weather seals are used on each side and above the dooropening, the bottom pad seals the underside. While additional padding inthe form of wedges and the like may be used they are subject toexcessive wear and abuse as trucks back into the loading dock. Ratherthan seal with stationary members that are impacted by the rear oftrucks, this invention provides for a series of pads carried by theleveler.

Referring now to FIGS. 7A, 7B, 7C, and 7D, a third embodiment of thisinvention is depicted. In these figures, common elements are given, thesame reference numbers as in prior embodiments. Thus, in FIGS. 7A and 7Bthe deck 10 is shown having a lip 32 hingedly coupled by means of thepivot 34. The bottom pad 60 is mounted to the deck in a manner, forexample, in the first embodiment. The underside of the deck has a seriesof U-shaped beams 31.

In accordance with this embodiment of the invention, a side seal 80 ismounted to either side of the deck by a fixing relative to a plate 82having rivets or the like. While FIG. 7B illustrates only a portion ofthe deck in front view, it would be understood that the side seal 80would be placed on both sides of the deck.

As illustrated in FIG. 7A, the seal may be mounted in an inclined memberattaching at one end to a lateral beam member 31 at each end of thedeck. Thus, the side seal 80 is affixed to a metal bracket 82 having aseries of rivets 84 adjoining those two elements together. The bracket82 is then fastened at one end to a bottom plate 33 of the deck assemblyand at a distal forward portion to a frame member 35. FIG. 7A alsoillustrates the extension of the side seal 80 above the hinge 34 toeffectively seal that portion. FIG. 7B illustrates the extension of theside seal beyond the lateral edge of the deck and the bottom pad 60.This side seal provides one portion of the system to effectively sealthe space between the deck and lip and the structure. FIGS. 7C and 7Dillustrate the remainder of the system. FIG. 7D is a section taken alongsection line D--D and FIG. 7C. As illustrated in FIGS. 7C and 7D, anadditional side seal 86 is mounted on the lip 32 by means of a flange88. The seal 86 is coupled to the flange 88 by means of rivets 90 or thelike. The flange is then attached to the lip in any conventional manner.As illustrated in FIG. 7C, the side seal on the lip thus pivots with thelip 32. It overlaps the area 92 between the deck 10 and the door frame94 which has mounted thereon front bumpers 96. Thus, as illustrated inFIG. 7C the wiping action of the side seal 86 provides an effective sealvia the lip to shut off the area 92. This, in combination with the sideseal on the deck as illustrated in FIGS. 7A and 7B, provides a means bywhich the opening between the leveler and the conventional weather pads96 are sealed.

It will be appreciated that various modifications of this invention canbe practiced without departing from the essential scope thereof.

What is claimed is:
 1. A vertically storing dock leveler comprising;adeck assembly, means at one end of deck assembly for hingedly mounting asaid deck assembly to a fixed surface, means to move said deck assemblyfrom an upright stored position to a horizontal operative position; alip pivotably mounted to an opposite end of said deck assembly, means tomove said lip and, a seal pivotably mounted on said deck assembly toclose a space between said deck assembly and a floor when said deckassembly is in an operative position.
 2. The vertically storing dockleveler of claim 1 wherein said seal extends over substantially thewidth of said deck assembly.
 3. The vertically storing dock leveler ofclaim 1 wherein said seal comprises a resilient foam covered withfabric.
 4. The vertically storing dock leveler of claim 1 wherein saidseal comprises an asymmetrically shaped resilient pad, said pad bucklingupon contact with said floor without substantial bulging to close saidspace as the deck assembly is lowered to a position below horizontal. 5.The vertically storing dock leveler of claim 1 wherein said seal ismounted on the underside of the deck assembly near said lip end.
 6. Thevertically storing dock leveler of claim 1 further comprising means topivotably attach said seal to an underside of said deck assembly.
 7. Thevertically storing leveler of claim 1 wherein said seal comprises awedge shaped resilient pad covered with fabric, said seal buckling andcompressing upon contact with said floor to close said space as the deckassembly is lowered.
 8. The vertically storing leveler of claim 1further comprising side rails on the deck assembly to prevent a vehiclefrom running off the side of the leveler.
 9. The vertically storing dockleveler of claim 1 wherein seal comprises a resilient pad tapered atboth ends, said pad buckling inward following contact with said floor toclose the space as said deck assembly is lowered below a horizontalposition.
 10. The vertically storing dock leveler of claim 1 furthercomprising means to said lock to deck assembly into said storedposition.
 11. A vertically storing dock leveler comprising:a hingedlymounted deck assembly having at one end a movable lip; means to movedeck assembly and lip, deck assembly mounted to a fixed surfaceincluding a generally horizontal floor, said deck assembly stored in asubstantially vertical position and lowered into a substantiallyhorizontal operative position, a first seal mounted on said deckassembly to close a space between deck assembly and floor when said deckassembly is in an operative position by contacting the ground anddeforming and, a second seal carried by said dock leveler to seal aspace between sides of said leveler and an adjacent surface.
 12. Thevertically storing dock leveler of claim 11 wherein said first sealextends beyond the width of deck assembly.
 13. The vertically storingdock leveler of claim 11 wherein first seal comprises a resilient foamcovered with fabric.
 14. The vertically storing dock leveler of claim 11wherein first seal comprises a wedge shaped resilient pad, said padbuckling upon contact with floor to close said space as deck assembly islowered and bending as no deck assembly is lowered below dock level. 15.The vertically storing dock leveler of claim 11 wherein second seal ismounted to sides of said deck assembly near said lip.
 16. The verticallystoring dock leveler of claim 11 wherein said second seal comprises awiping member mounted to said lip and wherein said second seal has aflange mounting it to said lip.
 17. The vertically storing leveler ofclaim 11 wherein said second seal comprises a first resilient wipermember mounted to said deck assembly and a second wiper member mountedto said lip, wherein said first and second wiper members seal a spacebetween said dock leveler and an adjacent lateral structure.
 18. Thevertically storing leveler of claim 11 further comprising side rails onthe deck assembly to prevent a vehicle from running off the side of saidleveler.
 19. The vertically storing dock leveler of claim 11 whereinfirst seal comprises a tapered resilient pad, wherein said pad deflectsupon contact with floor to close said space as the deck assembly islowered.
 20. The vertically storing dock leveler of claim 11 furthercomprising means to lock to the deck assembly in a stored position.